704 DAVIDHUME
Custom, then, is the great guide of human life. It is that principle alone which
renders our experience useful to us, and makes us expect, for the future, a similar train
of events with those which have appeared in the past. Without the influence of custom,
we should be entirely ignorant of every matter of fact beyond what is immediately
present to the memory and senses. We should never know to adjust means to ends, or to
employ our natural powers in the production of any effect. There would be an end at
once of all action, as well as of the chief part of speculation.
But here it may be proper to remark, that though our conclusions from experience
carry us beyond our memory and senses, and assure us of matters of fact which happened
in the most distant places and most remote ages, yet some fact must always be present to
the senses or memory, from which we may first proceed in drawing these conclusions.
A man, who should find in a desert country the remains of pompous buildings, would con-
clude that the country had, in ancient times, been cultivated by civilized inhabitants; but
did nothing of this nature occur to him, he could never form such an inference. We learn
the events of former ages from history; but then we must peruse the volumes in which this
instruction is contained, and thence carry up our inferences from one testimony to another,
till we arrive at the eyewitnesses and spectators of these distant events. In a word, if we
proceed not upon some fact, present to the memory or senses, our reasonings would be
merely hypothetical; and however the particular links might be connected with each other,
the whole chain of inferences would have nothing to support it, nor could we ever, by its
means, arrive at the knowledge of any real existence. If I ask why you believe any partic-
ular matter of fact, which you relate, you must tell me some reason; and this reason will be
some other fact, connected with it. But as you cannot proceed after this manner,in infinitum,
you must at last terminate in some fact, which is present to your memory or senses; or
must allow that your belief is entirely without foundation.
What, then, is the conclusion of the whole matter? A simple one; though, it must
be confessed, pretty remote from the common theories of philosophy. All belief of mat-
ter of fact or real existence is derived merely from some object, present to the memory or
senses, and a customary conjunction between that and some other object. Or in other
words; having found in many instances, that any two kinds of objects—flame and heat,
snow and cold—have always been conjoined together; if flame or snow be presented
anew to the senses, the mind is carried by custom to expect heat or cold, and to believe
that such a quality does exist, and will discover itself upon a nearer approach. This belief
is the necessary result of placing the mind in such circumstances. It is an operation of the
soul, when we are so situated, as unavoidable as to feel the passion of love, when we
senates. But the observation of any fraud or cruelty in private life is sufficient, with the aid of a little thought,
to give us the same apprehension; while it serves as an instance of the general corruption of human nature, and
shows us the danger which we must incur by reposing an entire confidence in mankind. In both cases, it is
experience which is ultimately the foundation of our inference and conclusion.
There is no man so young and experienced, as not to have formed, from observation, many general
and just maxims concerning human affairs and the conduct of life; but it must be confessed, that, when a man
comes to put these in practice, he will be extremely liable to error, till time and farther experience both enlarge
these maxims, and teach him their proper use and application. In every situation or incident, there are many
particular and seemingly minute circumstances, which the man of greatest talent is, at first, apt to overlook,
though on them the justness of his conclusions, and consequently the prudence of his conduct, entirely
depend. Not to mention, that, to a young beginner, the general observations and maxims occur not always on
the proper occasions, nor can be immediately applied with due calmness and distinction. The truth is, an
unexperienced reasoner could be no reasoner at all, were he absolutely unexperienced; and when we assign
that character to any one, we mean it only in a comparative sense, and suppose him possessed of experience,
in a smaller and more imperfect degree.